Java tutorial
/* Copyright (C) 2003-2015 JabRef contributors. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ package net.sf.jabref.exporter; import java.io.File; import java.util.Timer; import java.util.TimerTask; import net.sf.jabref.Globals; import net.sf.jabref.JabRefPreferences; import net.sf.jabref.gui.BasePanel; import net.sf.jabref.gui.JabRefFrame; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * Background task and utilities for autosave feature. */ public class AutoSaveManager { private static final Log LOGGER = LogFactory.getLog(AutoSaveManager.class); private final JabRefFrame frame; private Timer t; public AutoSaveManager(JabRefFrame frame) { this.frame = frame; } public void startAutoSaveTimer() { if (t != null) { // shut down any previously set timer to not leak any timers t.cancel(); } TimerTask task = new AutoSaveTask(); t = new Timer(); long interval = (long) 60000 * Globals.prefs.getInt(JabRefPreferences.AUTO_SAVE_INTERVAL); t.scheduleAtFixedRate(task, interval, interval); } public void stopAutoSaveTimer() { t.cancel(); } private class AutoSaveTask extends TimerTask { @Override public void run() { // Since this method is running in the background, we must be prepared that // there could be changes done by the user while this method is running. for (BasePanel panel : frame.getBasePanelList()) { if (panel.isModified() && (panel.getBibDatabaseContext().getDatabaseFile() != null)) { AutoSaveManager.autoSave(panel); } } } } /** * Get a File object pointing to the autosave file corresponding to the given file. * @param f The database file. * @return its corresponding autosave file. */ public static File getAutoSaveFile(File f) { return new File(f.getParentFile(), ".$" + f.getName() + '$'); } /** * Perform an autosave. * @param panel The BasePanel to autosave for. * @return true if successful, false otherwise. */ private static boolean autoSave(BasePanel panel) { File databaseFile = panel.getBibDatabaseContext().getDatabaseFile(); File backupFile = AutoSaveManager.getAutoSaveFile(databaseFile); try { SavePreferences prefs = SavePreferences.loadForSaveFromPreferences(Globals.prefs).withMakeBackup(false) .withEncoding(panel.getEncoding()); BibDatabaseWriter databaseWriter = new BibDatabaseWriter(); SaveSession ss = databaseWriter.saveDatabase(panel.getBibDatabaseContext(), prefs); ss.commit(backupFile); } catch (SaveException e) { LOGGER.error("Problem with automatic save", e); return false; } return true; } /** * Delete this BasePanel's autosave if it exists. * @param panel The BasePanel in question. * @return true if there was no autosave or if the autosave was successfully deleted, false otherwise. */ public static boolean deleteAutoSaveFile(BasePanel panel) { if (panel.getBibDatabaseContext().getDatabaseFile() == null) { return true; } File backupFile = AutoSaveManager.getAutoSaveFile(panel.getBibDatabaseContext().getDatabaseFile()); if (backupFile.exists()) { return backupFile.delete(); } else { return true; } } /** * Clean up by deleting the autosave files corresponding to all open files, * if they exist. */ public void clearAutoSaves() { for (BasePanel panel : frame.getBasePanelList()) { AutoSaveManager.deleteAutoSaveFile(panel); } } /** * Check if a newer autosave exists for the given file. * @param f The file to check. * @return true if an autosave is found, and if the autosave is newer * than the given file. */ public static boolean newerAutoSaveExists(File f) { File asFile = AutoSaveManager.getAutoSaveFile(f); return asFile.exists() && (asFile.lastModified() > f.lastModified()); } }